U.S. patent application number 14/560850 was filed with the patent office on 2015-06-25 for process for converting oxygenates to aromatic hydrocarbons.
The applicant listed for this patent is ExxonMobil Chemical Patents Inc.. Invention is credited to Jeevan S. Abichandani, Linelle T. Jacob, Stephen J. McCarthy, Machteld M. Mertens, John D. OU, Rohit Vijay.
Application Number | 20150175498 14/560850 |
Document ID | / |
Family ID | 51062732 |
Filed Date | 2015-06-25 |
United States Patent
Application |
20150175498 |
Kind Code |
A1 |
OU; John D. ; et
al. |
June 25, 2015 |
Process for Converting Oxygenates to Aromatic Hydrocarbons
Abstract
Embodiments of the invention provide processes for catalytically
converting oxygenates to hydrocarbon products having an increased
C.sub.6-C.sub.8 aromatics content therein. Particular processes
include (a) providing a first mixture comprising .gtoreq.10.0 wt. %
of at least one oxygenate, based on the weight of the first
mixture; (b) contacting the first mixture with a catalyst to
convert the first mixture to a product stream including water, one
or more hydrocarbons, hydrogen, and one or more oxygenates, wherein
the catalyst comprises at least one molecular sieve and at least
one element selected from Groups 2-14 of the Periodic Table and the
hydrocarbons comprise .gtoreq.30.0 wt. % of aromatics, based on the
weight of the hydrocarbons in the product stream; and (c)
separating from the product stream at least one water-rich stream,
at least one aromatic-rich hydrocarbon stream, and at least one
aromatic-depleted hydrocarbon stream.
Inventors: |
OU; John D.; (Houston,
TX) ; Mertens; Machteld M.; (Flemington, NJ) ;
Jacob; Linelle T.; (Humble, TX) ; McCarthy; Stephen
J.; (Center Valley, PA) ; Vijay; Rohit;
(Bridgewater, NJ) ; Abichandani; Jeevan S.;
(Houston, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Chemical Patents Inc. |
Baytown |
TX |
US |
|
|
Family ID: |
51062732 |
Appl. No.: |
14/560850 |
Filed: |
December 4, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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62003290 |
May 27, 2014 |
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61918984 |
Dec 20, 2013 |
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61918994 |
Dec 20, 2013 |
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61919013 |
Dec 20, 2013 |
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Current U.S.
Class: |
585/321 ;
585/322; 585/408 |
Current CPC
Class: |
C10G 2400/30 20130101;
C07C 1/24 20130101; C07C 5/2729 20130101; C07C 6/06 20130101; C10G
3/49 20130101; C07C 2/64 20130101; C07C 6/00 20130101; C07C 2529/40
20130101; C10G 29/205 20130101; Y02P 30/42 20151101; C07C 1/22
20130101; Y02P 30/20 20151101; Y02P 30/40 20151101 |
International
Class: |
C07C 1/22 20060101
C07C001/22; C07C 2/64 20060101 C07C002/64; C07C 5/27 20060101
C07C005/27; C07C 6/06 20060101 C07C006/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2014 |
EP |
14176022.3 |
Claims
1. An aromatic production process, comprising: (a) providing a
first mixture comprising .gtoreq.10.0 wt. % of at least one
oxygenate, based on the weight of the first mixture; (b) contacting
said first mixture with a catalyst to convert said first mixture to
a product stream comprising water, one or more hydrocarbons,
hydrogen, and one or more oxygenates, wherein (1) said catalyst
comprises at least one molecular sieve and at least one element
selected from Groups 2-14 of the Periodic Table, (2) said one or
more hydrocarbons comprise .gtoreq.30.0 wt. % of aromatics, based
on the weight of said one or more hydrocarbons in the product
stream; and (c) separating from said product stream (i) at least
one water-rich stream, (ii) at least one aromatic-rich hydrocarbon
stream, and (iii) at least one aromatic-depleted hydrocarbon
stream.
2. The process of claim 1, wherein the first mixture comprises
.gtoreq.90.0 wt. % of methanol and/or dimethylether and wherein the
process further comprises separating from the aromatic-rich
hydrocarbon stream (i) at least one first stream comprising
oxygenate and C.sub.6 and/or C.sub.7 aromatics, (ii) at least one
second stream comprising oxygenate and C.sub.8 aromatics, and (iii)
at least one third stream comprising oxygenate and C.sub.9+
aromatics.
3. The process of claim 2, further comprising contacting at least a
portion of the first stream with the catalyst in step (b).
4. The process of claim 2, further comprising separating from the
first stream a first oxygenate stream and a second aromatics-rich
stream, the aromatics-rich stream comprising C.sub.6 and/or C.sub.7
aromatics.
5. The process of claim 4, further comprising recovering benzene
and/or toluene from the second aromatics-rich stream.
6. The process of claim 4, further comprising sending at least a
portion of the second aromatics-rich stream to a toluene
alkylation, toluene disproportionation or transalkylation unit to
produce xylenes.
7. The process of claim 4, further comprising contacting at least a
portion of the first oxygenate stream with the catalyst in step
(b).
8. The process of claim 2, further comprising separating from the
second stream a second oxygenate stream and a third aromatics-rich
stream, the third aromatics-rich stream comprising C.sub.8+
aromatics.
9. The process of claim 8, further comprising recovering
para-xylene and a para-xylene depleted stream from the third
aromatics-rich stream.
10. The process of claim 9, further comprising sending at least a
portion of para-xylene depleted stream to a xylenes isomerization
unit to produce a mixed xylenes stream and recovering para-xylene
from the mixed xylenes stream.
11. The process of claim 8, further comprising contacting at least
a portion of the second oxygenate stream with the catalyst in step
(b).
12. The process of claim 2, further comprising separating from the
third stream a third oxygenate stream and a fourth aromatics-rich
stream, the fourth aromatics-rich stream comprising C.sub.9+
aromatics.
13. The process of claim 12, further comprising transalkylating at
least a portion of the fourth aromatics-rich stream to produce
xylenes.
14. The process of claim 12, further comprising contacting at least
a portion of the third oxygenate stream with the catalyst in step
(b).
15. The process of claim 1, further comprising contacting at least
a portion of the aromatic-depleted hydrocarbon stream with the
catalyst in step (b).
16. The process of claim 1, further comprising recovering
oxygenates from the aromatic-depleted hydrocarbon stream.
17. The process of claim 16, comprising contacting the catalyst in
step (b) with at least a portion of the recovered oxygenates.
18. The process of claim 16, further comprising recovering at least
one of ethylene, propylene, and butylenes from at least a portion
of the aromatic-depleted hydrocarbon stream.
19. The process of claim 1, wherein the molecular sieve comprises
ZSM-5, and the element comprises Zn.
20. An oxygenate conversion process, the process comprising: (a)
providing a first mixture, the first mixture comprising
.gtoreq.10.0 wt. % oxygenate based on the weight of the first
mixture; (b) exposing the first mixture at a temperature
.gtoreq.400.degree. C. at a pressure .gtoreq.2 bar absolute in the
presence of a catalyst to convert .gtoreq.90.0 wt. % of the first
mixture's oxygenate to (i) water, (ii) hydrocarbon, and (iii)
.ltoreq.1.0 wt. % carbon monoxide, the weight percents being based
on the weight of oxygenate in the first mixture, wherein (1) the
catalyst comprises .gtoreq.10.0 wt. % of at least one molecular
sieve and .gtoreq.0.1 wt. % of at least one element selected from
Groups 2-14 of the Periodic Table, the weight percents being based
on the weight of the catalyst, and (2) the hydrocarbon comprises
.gtoreq.50.0 wt. % of aromatics, based on the weight of the
hydrocarbon; and (c) separating the aromatics from one or more of
(i) at least a portion of the water produced in step (b), (ii) any
unreacted oxygenate, and/or (iii) at least a portion of the
hydrocarbon.
21. The process of claim 20, wherein (i) the first mixture
comprises .gtoreq.25.0 wt. % oxygenate, based on the weight of the
first mixture, and (ii) the oxygenate comprises .gtoreq.90.0 wt. %
based on the weight of the oxygenate of one or more of alcohol,
ether, carboxylic acid, carbon monoxide, or carbon dioxide.
22. The process of claim 21, wherein the oxygenate comprises
.gtoreq.99.0 wt. % of methanol and/or dimethylether.
23. The process of claim 22, wherein the oxygenate comprises
.gtoreq.99.0 wt. % of methanol, the exposing of step (b) is
conducted at a weight hourly space velocity in the range of from
0.5 to 12 hr.sup.-1, the hydrocarbon comprises .gtoreq.80.0 wt. %
of aromatics, based on the weight of the hydrocarbon, and
.ltoreq.30.0 wt. % of the aromatics comprise durene, based on the
weight of the aromatics.
24. The process of claim 20, wherein the first mixture further
comprises .gtoreq.10.0 wt. % aromatics, based on the weight of the
first mixture.
25. The process of claim 20, further comprising recycling at least
a portion of the separated aromatics from step (c) to step (a),
wherein .gtoreq.50.0 wt. % of the first mixture's aromatics are the
recycled aromatics.
26. The process of claim 20, wherein the molecular sieve comprises
ZSM-5, and the element comprises Zn.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Provisional U.S. Patent
Application Ser. No. 62/003,290 (Docket No. 2014EM128), filed May
27, 2014; Provisional U.S. Patent Application Ser. No. 61/918,984
(Docket No. 2013EM376) filed Dec. 20, 2013; Provisional U.S. Patent
Application Ser. No. 61/918,994 (Docket No. 2013EM377) filed Dec.
20, 2013; Provisional U.S. Patent Application Ser. No. 61/919,013
(Docket No. 2013EM378) filed Dec. 20, 2013; and EP 14176022.3
(Docket No. 2014EM128) filed Jul. 7, 2014, the disclosures of which
are incorporated herein by reference in their entireties. Related
applications to which priority is not claimed are U.S. patent
application Ser. No. ______, (Docket No. 2014EM360US), filed Dec.
4, 2014; P.C.T. Patent Application No. ______, (Docket No.
2014EM360PCT), filed Dec. 4, 2014; U.S. patent application Ser. No.
______, (Docket No. 2014EM359US), filed Dec. 4, 2014; and P.C.T.
Patent Application No. ______, (Docket No. 2014EM359PCT), filed
Dec. 4, 2014.
FIELD OF THE INVENTION
[0002] Embodiments of the invention relate to processes for
converting oxygenates to aromatic hydrocarbons. In particular,
embodiments of the invention related to the conversion of methanol
to C.sub.6-C.sub.8 aromatic hydrocarbons.
BACKGROUND OF THE INVENTION
[0003] Aromatic hydrocarbons, such as benzene, toluene, xylene,
etc. are useful as fuels, solvents, and as feeds for various
chemical processes. Of the aromatics, those having 6 to 8 carbon
atoms (e.g., benzene, toluene, and xylene) are especially desired.
Para-xylene ("p-xylene") is particularly useful for manufacturing
phthalic acids such as terephthalic acid, which is an intermediate
in the manufacture of synthetic fibers such as polyester
fibers.
[0004] One conventional process for producing aromatics involves
reacting an oxygenate, such as methanol, in the presence of
zeolite, such as ZSM-5, to produce water and a hydrocarbon product
containing aromatics. See, e.g., C. D. Chang and A. J. Silvestri,
Journal of Catalysis 47, p. 249 (1977), which discloses a process
featuring high methanol conversion in approximately stoichiometric
yield to produce about 44 wt. % hydrocarbon and about 56 wt. % of
water, based on total product weight. Water and a portion of the
hydrocarbon are condensed by exposing the product to a temperature
<100.degree. C., with the vapor being recycled to the reactor
inlet. The vapor, which comprises about 20 wt. % of the hydrocarbon
product, contains primarily C.sub.1-C.sub.4 paraffin and
C.sub.2-C.sub.4 olefin. At a reaction temperature of about
370.degree. C. and a liquid hourly space velocity (LHSV) of
approximately 1.0 hr.sup.-1, approximately 80 wt. % of the
hydrocarbon product comprises gasoline boiling-range hydrocarbons,
including C.sub.6-C.sub.11 aromatics. Under these conditions, the
hydrocarbon product comprises approximately 30 wt. % of
C.sub.6-C.sub.8 aromatics and approximately 10 wt. % of C.sub.9+
hydrocarbon, primarily 1,2,4,5-tetramethylbenzene (i.e., durene).
Durene can be removed by selectively hydrotreating the aromatic
portion of the hydrocarbon product.
[0005] It is desired to convert oxygenates to hydrocarbons with an
increase in the relative amount of C.sub.6-C.sub.8 aromatics in the
hydrocarbon product as the C.sub.6-C.sub.8 aromatics are
commercially useful. It is particularly desired to do so without
increasing (i) the relative amount of durene in the aromatic
portion of the hydrocarbon product to avoid extensively treating
the product to remove durene toxic and/or (ii) the rate of catalyst
deactivation. It is even more desired to do this while increasing
the relative amount of p-xylene in the hydrocarbon product since
p-xylene is the most commercially desired of the C.sub.6-C.sub.8
aromatics.
SUMMARY OF THE INVENTION
[0006] It has been found that oxygenates can be catalytically
converted to hydrocarbon products having an increased
C.sub.6-C.sub.8 aromatics content in the hydrocarbon product
compared to conventional processes. The process utilizes a catalyst
comprising (i) .gtoreq.10.0 wt. % of at least one molecular sieve
and (ii) .gtoreq.0.1 wt. % of at least one element selected from
Groups 2-14 of the Periodic Table. The invention is based in part
on the discovery that utilizing one or more elements from Groups
2-14 of the Periodic Table provides the catalyst with a
dehydrogenation functionality that surprisingly produces molecular
hydrogen and an increased aromatics yield, but without producing a
significant amount of carbon monoxide.
[0007] It has also been found that recycling and combining at least
a portion of the aromatics in the hydrocarbon product with the
oxygenate unexpectedly leads to one or more of the following
advantages. In particular embodiments, recycling and combining at
least a portion of the aromatics in the hydrocarbon product
provides an increase in the relative amount of aromatics in the
hydrocarbon product. The increase in aromatics may be achieved
without a significant increase in the rate of catalyst deactivation
and/or without a significant increase in the relative amount of
durene in the aromatic portion of the hydrocarbon product.
Advantageously and contrary to expectations, recycling and
combining with the oxygenate at least a portion of the aromatics in
the hydrocarbon product does not suppress methanol conversion to
aromatic products. Under particular conditions, recycling of the
aromatics can actually provide an overall increase in product
aromatics content. Surprisingly, the catalyst may not experience a
significant increase in deactivation rate, e.g., from over-reacting
the recycled aromatics, even at elevated reaction temperatures
(e.g., end of run conditions). And under certain conditions, the
relative amount of durene in the aromatic portion of the product
may not increase, even though recycling of xylenes to a chemical
environment rich in CH.sub.2 fragments would be expected to result
in alkylation to C.sub.9+ aromatics. At least a portion of the
olefins and paraffins in the hydrocarbon product may be recycled as
well, leading to further conversion of the olefins and paraffins to
aromatics without causing a significant increase in catalyst
deactivation.
[0008] The process can be operated continuously, semi-continuously,
or even in batch mode. The catalyst can be located within a
reactor, e.g., in one or more fixed beds. More than one reactor can
be utilized, the reactors being arranged, e.g., in series,
parallel, or series-parallel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a process according to an embodiment of
the invention.
[0010] FIG. 2 illustrates a process according to an embodiment of
the invention wherein an aromatic-rich hydrocarbon stream is
separated into first, second and third streams.
[0011] FIG. 3 illustrates a process according to an embodiment of
the invention wherein the first stream is separated into a first
oxygenate stream and a second aromatics-rich stream comprising
C.sub.6 and/or C.sub.7 aromatics.
[0012] FIG. 4 illustrates a process according to an embodiment of
the invention wherein the second stream is separated into a second
oxygenate stream and a third aromatics-rich stream.
[0013] FIG. 5 illustrates a process according to an embodiment of
the invention wherein the third stream is separated into a third
oxygenate stream and a fourth aromatics-rich stream comprising
C.sub.9+ aromatics.
DETAILED DESCRIPTION
[0014] The present process is useful for the conversion a first
mixture comprising oxygen-containing organic compounds (i.e.,
"oxygenates") into hydrocarbon products where the conversion is
carried out by an exothermic catalytic reaction.
[0015] As used herein the phrase "at least a portion of" means 1.0
to 100.0 wt. % of the process stream or composition to which the
phrase refers. The upper limit on the range to which the phrase "at
least a portion of" refers, may be 1.0 wt. %, 2.0 wt. %, 5.0 wt. %,
10.0 wt. %, 20.0 wt. %, 25.0 wt. %, 30.0 wt. %, 40.0 wt. %, 50.0
wt. %, 60.0 wt. %, 70.0 wt. %, 75.0 wt. %, 80.0 wt. %, 90.0 wt. %,
95.0 wt. %, 98.0 wt. %, 99.0 wt. %, or 100.0 wt. %. The lower limit
on the range to which the phrase "at least a portion of" refers may
be selected from 1.0 wt. %, 2.0 wt. %, 5.0 wt. %, 10.0 wt. %, 20.0
wt. %, 25.0 wt. %, 30.0 wt. %, 40.0 wt. %, 50.0 wt. %, 60.0 wt. %,
70.0 wt. %, 75.0 wt. %, 80.0 wt. %, 90.0 wt. %, 95.0 wt. %, 98.0
wt. %, 99.0 wt. %, or 100.0 wt. %. Ranges expressly disclosed
include combinations of any of the above-enumerated upper and lower
limits; e.g., 10.0 to 100.0 wt. %, 10.0 to 98.0 wt. %, 2.0 to 10.0,
40.0 to 60.0 wt. %, etc.
[0016] The initial feedstream or "first mixture" used herein is a
hydrocarbon-containing composition including one or more
oxygenates. Typically, the first mixture comprises .gtoreq.10.0 wt.
% of at least one oxygenate, based on the weight of the first
mixture. The upper limit on the amount of oxygenate(s) in the first
mixture may be 10.0 wt. %, 12.5 wt. %, 15.0 wt. %, 20.0 wt. %, 25.0
wt. %, 30.0 wt., 35.0 wt. % 40.0 wt. %, 45.0 wt. %, 50.0 wt. %,
55.0 wt. %, 60.0 wt. %, 65.0 wt. %, 70.0 wt. %, 75.0 wt. %, 80.0
wt. %, 85.0 wt. %, 90.0 wt. %, 95.0 wt. %, 99.0 wt. %, 99.5 wt. %,
or 100.0 wt. %. The lower limit on the amount of oxygenate in the
first mixture may be 10.0 wt. %, 12.5 wt. %, 15.0 wt. %, 20.0 wt.
%, 25.0 wt. %, 30.0 wt. %, 35.0 wt. % 40.0 wt. %, 45.0 wt. %, 50.0
wt. %, 55.0 wt. %, 60.0 wt. %, 65.0 wt. %, 70.0 wt. %, 75.0 wt. %,
80.0 wt. %, 85.0 wt. %, 90.0 wt. %, 95.0 wt. %, 99.0 wt. %, 99.5
wt. %, or 100.0 wt. %. Ranges expressly disclosed include
combinations of any of the above-enumerated upper and lower limits;
e.g., 10.0 to 100.0 wt. %, 12.5 to 99.5 wt. %, 20.0 to 90.0, 50.0
to 99.0 wt. %, etc.
[0017] As used herein the term "oxygenate", and "oxygenate
composition," and the like refer to oxygen-containing compounds
having 1 to about 50 carbon atoms, 1 to about 20 carbon atoms, 1 to
about 10 carbon atoms, or 1 to about 4 carbon atoms. Exemplary
oxygenates include alcohols, ethers, carbonyl compounds, e.g.,
aldehydes, ketones and carboxylic acids, and mixtures thereof.
Particular oxygenates include methanol, ethanol, dimethyl ether,
diethyl ether, methylethyl ether, di-isopropyl ether, dimethyl
carbonate, dimethyl ketone, formaldehyde, and acetic acid.
[0018] In particular embodiments, the oxygenate comprises one or
more alcohols, preferably alcohols having 1 to about 20 carbon
atoms, 1 to about 10 carbon atoms, or 1 to about 4 carbon atoms.
The alcohols useful as first mixtures may be linear or branched,
substituted or unsubstituted aliphatic alcohols and their
unsaturated counterparts. Non-limiting examples of such alcohols
include methanol, ethanol, propanols (e.g., n-propanol,
isopropanol), butanols (e.g., n-butanol, sec-butanol, tert-butyl
alcohol), pentanols, hexanols, etc. and mixtures thereof. In any
embodiment described herein, the first mixture may be one or more
of methanol, and/or ethanol, particularly methanol. In any
embodiment, the first mixture may be methanol and dimethyl
ether.
[0019] The oxygenate, particularly where the oxygenate comprises an
alcohol (e.g., methanol), may optionally be subjected to
dehydration, e.g., catalytic dehydration over .gamma.-alumina.
Typically, such catalytic dehydration decreases the amount of water
in the oxygenate by converting a portion of the water and alcohol
to an ether, e.g., dimethyl ether (DME), in the first mixture.
Further optionally, at least a portion of any methanol and/or water
remaining in the first mixture after catalytic dehydration may be
separated from the first mixture.
[0020] In any embodiment, one or more other compounds may be
present in the first mixture. Some common or useful such compounds
have 1 to about 50 carbon atoms, 1 to about 20 carbon atoms, 1 to
about 10 carbon atoms, or 1 to about 4 carbon atoms. Typically,
although not necessarily, such compounds include one or more
heteroatoms other than oxygen. Some such compounds include amines,
halides, mercaptans, sulfides, and the like. Particular such
compounds include alkyl-mercaptans (e.g., methyl mercaptan and
ethyl mercaptan), alkyl-sulfides (e.g., methyl sulfide),
alkyl-amines (e.g., methyl amine), alkyl-halides (e.g., methyl
chloride and ethyl chloride). In particular embodiments, the first
mixture includes one or more of .gtoreq.1.0 wt. % acetylene,
pyrolysis oil or aromatics, particularly C.sub.6 and/or C.sub.7
aromatics. The upper limit on the amount of such other compounds in
the first mixture may be 2.0 wt. %, 5.0 wt. %, 10.0 wt. %, 15.0 wt.
%, 20.0 wt. %, 25.0 wt. %, 30.0 wt. %, 35.0 wt. %, 40.0 wt. %, 45.0
wt. %, 50.0 wt. %, 60.0 wt. %, 75.0 wt. %, 90.0 wt. %, or 95.0 wt.
%. The lower limit on the amount of such other compounds in the
first mixture may be 2.0 wt. %, 5.0 wt. %, 10.0 wt. %, 15.0 wt. %,
20.0 wt. %, 25.0 wt. %, 30.0 wt. %, 35.0 wt. %, 40.0 wt. %, 45.0
wt. %, 50.0 wt. %, 60.0 wt. %, 75.0 wt. %, or 90.0 wt. %. Ranges
expressly disclosed include combinations of any of the
above-enumerated upper and lower limits; e.g., 1.0 to 10.0 wt. %,
2.0 to 5.0 wt. %, 10.0 to 95.0 wt. %, wt. %, 15.0 to 90.0 wt. %,
20.0 to 75.0 wt. %, 25.0 to 60 wt. %, 30.0 to 50 wt. %, 35.0 to 45
wt. %, about 40.0 wt. %, etc.
[0021] The catalyst used herein is a composition of matter
comprising a molecular sieve and a Group 2-14 element of the
Periodic Table. In this sense, the term "comprising" can also mean
that the catalyst can comprise the physical or chemical reaction
product of the molecular sieve and the Group 2-14 element.
Optionally, the catalyst may also include a filler or binder and
may be combined with a carrier to form slurry.
[0022] For the purposes of this description and claims, reference
to a group number for an element corresponds to the current IUPAC
numbering scheme for the periodic table. Therefore, a "Group 4
metal" is an element from Group 4 of the Periodic Table, e.g., Hf,
Ti, or Zr. The more preferred molecular sieves are SAPO molecular
sieves, and metal-substituted SAPO molecular sieves. In particular
embodiments, one or more Group 2 elements (e.g., Be, Mg, Ca, Sr,
Ba, and Ra) may be used. In other embodiments, one or more Group 3
elements (e.g., Sc and Y), a Lanthanide (e.g., La, Ce, Pr, Nd, Sm,
Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), and/or an Actinide may be
used. Catalysts comprising at least one Group 4 transition metal
(e.g., Ti, Zr, and Hf) may be particularly useful. Likewise, some
catalysts may benefit from the presence of at least one Group 5
and/or Group 6 element (e.g., V, Nb, Ta, Cr, Mo, and W). One or
more Group 7-9 element (e.g., Mn, Tc, Re, Fe, Ru, Os, Co, Rh, and
Ir) may also be used. In some embodiments, the Group 2-14 element
comprises one or more Group 11 and/or Group 12 elements (e.g., Cu,
Ag, Au, Zn, and Cd) may be used. In still other embodiments, one or
more Group 13 elements (B, Al, Ga, In, and Tl). In a preferred
embodiment, the metal is selected from the group consisting of Zn,
Cd, Ag, and Cu, ideally Zn.
[0023] The molecular sieve comprises .gtoreq.10.0 wt. % of the
catalyst. The upper limit on the amount of molecular sieve in the
catalyst may be 10.0 wt. %, 12.5 wt. %, 15.0 wt. %, 20.0 wt. %,
25.0 wt. %, 30.0 wt. %, 35.0 wt. % 40.0 wt. %, 45.0 wt. %, 50.0 wt.
%, 55.0 wt. %, 60.0 wt. %, 65.0 wt. %, 70.0 wt. %, 75.0 wt. %, 80.0
wt. %, 85.0 wt. %, 90.0 wt. %, 95.0 wt. %, 99.0 wt. %, 99.5 wt. %,
or 100.0 wt. %. The lower limit on the amount of molecular sieve in
the catalyst may be 10.0 wt. %, 12.5 wt. %, 15.0 wt. %, 20.0 wt. %,
25.0 wt. %, 30.0 wt. %, 35.0 wt. % 40.0 wt. %, 45.0 wt. %, 50.0 wt.
%, 55.0 wt. %, 60.0 wt. %, 65.0 wt. %, 70.0 wt. %, 75.0 wt. %, 80.0
wt. %, 85.0 wt. %, 90.0 wt. %, 95.0 wt. %, 99.0 wt. %, 99.5 wt. %,
or 100.0 wt. %. Ranges expressly disclosed include combinations of
any of the above-enumerated upper and lower limits; e.g., 10.0 to
20.0 wt. %, 12.5 to 25.0 wt. %, 20.0 to 50.0, or 40.0 to 99.0 wt.
%.
[0024] As used herein the term "molecular sieve" refers to
crystalline or non-crystalline materials having a porous structure.
Microporous molecular sieves typically have pores having a diameter
of .ltoreq.about 2.0 nm. Mesoporous molecular sieves typically have
pores with diameters of about 2 to about 50 nm. Macroporous
molecular sieves have pore diameters of >50.0 nm. The upper
limit on the pore diameter may be 1.00.times.10.sup.4 nm,
5.00.times.10.sup.3 nm, 2.50.times.10.sup.3 nm, 1.00.times.10.sup.3
nm, 5.00.times.10.sup.2 nm, 2.50.times.10.sup.2 nm,
1.25.times.10.sup.2 nm, 75.0 nm, 50.0 nm, 40.0 nm, 30.0 nm, 20.0
nm, 10.0 nm, or 5.0 nm. The lower limit on the pore diameter may be
5.00.times.10.sup.3 nm, 2.50.times.10.sup.3 nm, 1.00.times.10.sup.3
nm, 5.00.times.10.sup.2 nm, 2.50.times.10.sup.2 nm,
1.25.times.10.sup.2 nm, 75.0 nm, 50.0 nm, 40.0 nm, 30.0 nm, 20.0
nm, 10.0 nm, 5.0 nm, 4.0 nm, 3.0 nm, 2.0 nm, 1.0 nm or less. Ranges
of the pore diameters expressly disclosed include combinations of
any of the above-enumerated upper and lower limits. For example,
some molecular sieves may have pore diameters of about 1.0 to
>5.00.times.10.sup.3 nm, 2.0 to 5.00.times.10.sup.3 nm, 2.0 to
1.00.times.10.sup.3 nm, 2.0 to 5.00.times.10.sup.2 nm, 2.0 to
2.50.times.10.sup.2 nm, 2.0 to 1.25.times.10.sup.2 nm, 2.0 to 75.0
nm, 5.0 to 75.0 nm, 7.5 to 75.0 nm, 10.0 to 75.0 nm, 15.0 to 75.0
nm, 20.0 to 75.0 nm, 25.0 to 75.0 nm, 2.0 to 50.0 nm, 5.0 to 50.0
nm, 7.5 to 50.0 nm, 10.0 to 50.0 nm, 15.0 to 50.0 nm, 20.0 to 50.0
nm, or 25.0 to 50.0 nm, etc.
[0025] Additionally or alternatively, some molecular sieves useful
herein are described by a Constraint Index of about 1 to about 12.
The upper limit on the range of the Constraint Index may be about
12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, or 2.0. The
lower limit on the range of the Constraint Index may be about 11.0,
10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, or 1.0. Ranges of the
Constraint Indices expressly disclosed include combinations of any
of the above-enumerated upper and lower limits. For example, some
molecular sieves have a Constraint Index of 1.0 to about 10.0, 1.0
to about 8.0, 1 to about 6.0, 1 to about 5.0, 1 to about 3.0, 2.0
to about 11.0, 3.0 to 10.0, 4.0 to 9.0, or 6.0 to 9.0, etc.
Constraint Index is determined as described in U.S. Pat. No.
4,016,218, incorporated herein by reference for details of the
method.
[0026] Particular molecular sieves are zeolitic materials. Zeolitic
materials are crystalline or para-crystalline materials. Some
zeolites are aluminosilicates comprising [SiO.sub.4] and
[AlO.sub.4] units. Other zeolites are aluminophosphates (AlPO)
having structures comprising [AlO.sub.4] and [PO.sub.4] units.
Still other zeolites are silicoaluminophosphates (SAPO) comprising
[SiO.sub.4], [AlO.sub.4], and [PO.sub.4] units.
[0027] Non-limiting examples of SAPO and AlPO molecular sieves
useful herein include one or a combination of SAPO-5, SAPO-8,
SAPO-11, SAPO-16, SAPO-17, SAPO-18, SAPO-20, SAPO-31, SAPO-34,
SAPO-35, SAPO-36, SAPO-37, SAPO-40, SAPO-41, SAPO-42, SAPO-44,
SAPO-47, SAPO-56, AlPO-5, AlPO-11, AlPO-18, AlPO-31, AlPO-34,
AlPO-36, AlPO-37, AlPO-46, and metal containing molecular sieves
thereof. Of these, particularly useful molecular sieves are one or
a combination of SAPO-18, SAPO-34, SAPO-35, SAPO-44, SAPO-56,
AlPO-18, AlPO-34 and metal containing derivatives thereof, such as
one or a combination of SAPO-18, SAPO-34, AlPO-34, AlPO-18, and
metal containing derivatives thereof, and especially one or a
combination of SAPO-34, AlPO-18, and metal containing derivatives
thereof.
[0028] Additionally or alternatively, the molecular sieves useful
herein may be characterized by a ratio of Si to Al. In particular
embodiments, the molecular sieves suitable herein include those
having a Si/Al ratio of about 10 to 100, preferably about 10 to 80,
more preferably about 20 to 60, and most preferably about 20 to
40.
[0029] In an embodiment, the molecular sieve is an intergrowth
material having two or more distinct crystalline phases within one
molecular sieve composition. In particular, intergrowth molecular
sieves are described in U.S. Patent Application Publication No.
2002-0165089 and International Publication No. WO 98/15496,
published Apr. 16, 1998, both of which are herein fully
incorporated by reference.
[0030] Particular molecular sieves useful in this invention include
ZSM-5 (U.S. Pat. No. 3,702,886 and Re. 29,948); ZSM-11 (U.S. Pat.
No. 3,709,979); ZSM-12 (U.S. Pat. No. 3,832,449); ZSM-22 (U.S. Pat.
No. 4,556,477); ZSM-23 (U.S. Pat. No. 4,076,842); ZSM-34 (U.S. Pat.
No. 4,079,095) ZSM-35 (U.S. Pat. No. 4,016,245); ZSM-48 (U.S. Pat.
No. 4,397,827); ZSM-57 (U.S. Pat. No. 4,046,685); and ZSM-58 (U.S.
Pat. No. 4,417,780). The entire contents of the above references
are incorporated by reference herein. Other useful molecular sieves
include MCM-22, PSH-3, SSZ-25, MCM-36, MCM-49 or MCM-56, with
MCM-22. Still other molecular sieves include Zeolite T, ZKS,
erionite, and chabazite.
[0031] The catalyst also includes at least one element selected
from Groups 2-14 of the Periodic Table. Typically, the total weight
of the Group 2-14 elements is .gtoreq.0.1 wt. % based on the total
weight of the catalyst. Typically, the total weight of the Group
2-14 element is .ltoreq.about 10.0 wt. %, based on the total weight
of the catalyst. Thus, the upper limit on the range of the amount
of the Group 2-14 elements added to the molecular sieve may be 10.0
wt. %, 9.0 wt. %, 8.0 wt. %, 7.0 wt. %, 6.0 wt. %, 5.0 wt. %, 4.0
wt. %, 3.0 wt. %, 2.0 wt. %, 1.0 wt. %, or 0.1 wt. %. The lower
limit on the range of the amount of the Group 2-14 elements added
to the molecular sieve may be 10.0 wt. %, 9.0 wt. %, 8.0 wt. %, 7.0
wt. %, 6.0 wt. %, 5.0 wt. %, 4.0 wt. %, 3.0 wt. %, 2.0 wt. %, 1.0
wt. %, or 0.1 wt. %. Ranges expressly disclosed include
combinations of any of the above-enumerated upper and lower limits;
e.g., 0.1 to 10.0 wt. %, 0.1 to 8.0 wt. %, 0.1 to 6.0 wt. %, 0.1 to
5.0 wt. %, 0.1 to 4.0 wt. %, 0.1 to 3.0 wt. %, 0.1 to 2.0 wt. %,
0.1 to 1.0 wt. %, 1.0 to 10.0 wt. %, 1.0 to 9.0 wt. %, 1.0 to 8.0
wt. %, 1.0 to 7.0 wt. %, 1.0 to 6.0 wt. %, 1.0 to 5.0 wt. %, 1.0 to
4.0 wt. %, 1.0 to 3.0 wt. %, etc. Of course, the total weight of
the Group 2-14 elements shall not include amounts attributable to
the molecular sieve itself.
[0032] Particular molecular sieves and Group 2-14-containing
derivatives thereof have been described in detail in numerous
publications including for example, U.S. Pat. No. 4,567,029 (MeAPO
where Me is Mg, Mn, Zn, or Co), U.S. Pat. No. 4,440,871 (SAPO),
European Patent Application EP-A-0 159 624 (E1APSO where E1 is Be,
B, Cr, Co, Ga, Fe, Mg, Mn, Ti, or Zn), U.S. Pat. No. 4,554,143
(FeAPO), U.S. Pat. Nos. 4,822,478, 4,683,217, 4,744,885 (FeAPSO),
EP-A-0 158 975 and U.S. Pat. No. 4,935,216 (ZnAPSO, EP-A-0 161 489
(CoAPSO), EP-A-0 158 976 (ELAPO, where EL is Co, Fe, Mg, Mn, Ti, or
Zn), U.S. Pat. No. 4,310,440 (AlPO4), U.S. Pat. No. 5,057,295
(BAPSO), U.S. Pat. No. 4,738,837 (CrAPSO), U.S. Pat. Nos.
4,759,919, and 4,851,106 (CrAPO), U.S. Pat. Nos. 4,758,419,
4,882,038, 5,434,326, and 5,478,787 (MgAPSO), U.S. Pat. No.
4,554,143 (FeAPO), U.S. Pat. Nos. 4,686,092, 4,846,956, and
4,793,833 (MnAPSO), U.S. Pat. Nos. 5,345,011 and 6,156,931 (MnAPO),
U.S. Pat. No. 4,737,353 (BeAPSO), U.S. Pat. No. 4,940,570 (BeAPO),
U.S. Pat. Nos. 4,801,309, 4,684,617, and 4,880,520 (TiAPSO), U.S.
Pat. Nos. 4,500,651, 4,551,236, and 4,605,492 (TiAPO), U.S. Pat.
Nos. 4,824,554, 4,744,970 (CoAPSO), U.S. Pat. No. 4,735,806
(GaAPSO) EP-A-0 293 937 (QAPSO, where Q is framework oxide unit
[QO2]), as well as U.S. Pat. Nos. 4,567,029, 4,686,093, 4,781,814,
4,793,984, 4,801,364, 4,853,197, 4,917,876, 4,952,384, 4,956,164,
4,956,165, 4,973,785, 5,241,093, 5,493,066, and 5,675,050, all of
which are herein fully incorporated by reference. Other molecular
sieves include those described in R. Szostak, Handbook of Molecular
Sieves, Van Nostrand Reinhold, New York, N.Y. (1992), which is
herein fully incorporated by reference.
[0033] In one embodiment, the molecular sieve as modified by the
Group 2-14 element is a ZSM-5 based molecular sieve and the Group
2-14, element is selected from elements of Groups 11-12,
particularly Zn.
[0034] Various methods for synthesizing molecular sieves or
modifying molecular sieves are described in U.S. Pat. No. 5,879,655
(controlling the ratio of the templating agent to phosphorus), U.S.
Pat. No. 6,005,155 (use of a modifier without a salt), U.S. Pat.
No. 5,475,182 (acid extraction), U.S. Pat. No. 5,962,762 (treatment
with transition metal), U.S. Pat. Nos. 5,925,586 and 6,153,552
(phosphorus modified), U.S. Pat. No. 5,925,800 (monolith
supported), U.S. Pat. No. 5,932,512 (fluorine treated), U.S. Pat.
No. 6,046,373 (electromagnetic wave treated or modified), U.S. Pat.
No. 6,051,746 (polynuclear aromatic modifier), U.S. Pat. No.
6,225,254 (heating template), International Patent Application WO
01/36329 published May 25, 2001 (surfactant synthesis),
International Patent Application WO 01/25151 published Apr. 12,
2001 (staged acid addition), International Patent Application WO
01/60746 published Aug. 23, 2001 (silicon oil), U.S. Patent
Application Publication No. 2002-0055433 published May 9, 2002
(cooling molecular sieve), U.S. Pat. No. 6,448,197 (metal
impregnation including copper), U.S. Pat. No. 6,521,562 (conductive
microfilter), and U.S. Patent Application Publication No.
2002-0115897 published Aug. 22, 2002 (freeze drying the molecular
sieve), which are all herein incorporated by reference in their
entirety.
[0035] A process for converting an oxygenate-containing first
mixture to a hydrocarbon stream containing aromatic molecules in
the present of the catalyst described above will now be described.
FIG. 1 schematically illustrates a process 100 wherein an
oxygenated-containing feed is provided via line 101 to a reactor
103 and/or, optionally, to an optional dehydration unit 102 and
then or to a reactor 103. Reactor 103 may be any reactor suitable
for converting an oxygenate-containing first mixture to an
aromatics-containing hydrocarbon effluent. In any embodiment, the
reactor 103 may include one or more batch reactor or fixed bed
reactor having the catalyst therein, Where reactor 103 includes
more than one reactor, the reactors may be arranged in any suitable
configuration, e.g., in series, parallel, or series-parallel.
Typically, but not necessarily, the reactor 103 is a fixed-bed
reactor.
[0036] Reactor 103 is operated under conditions to produce a
product stream comprising water, one or more hydrocarbons,
hydrogen, and one or more oxygenates, wherein said one or more
hydrocarbons comprise .gtoreq.30.0 wt. % of aromatics, based on the
weight of said one or more hydrocarbons in the product stream. In
particular embodiments, the amount of aromatics in the hydrocarbon
may be 30.0 to 100.0 wt. %, 40.0 to 100.0 wt. %, 50.0 to 100.0 wt.
%, 60.0 to 100 wt. %, 70.0 to 100.0 wt. %, 80.0 to 100.0 wt. %,
90.0 to 100.0 wt. %, 95.0 to 100 wt. %; 30.0 to 95.0 wt. %, 40.0 to
95.0 wt. %, 50.0 to 95.0 wt. %, 60.0 to 95 wt. %, 70.0 to 95.0 wt.
%, 80.0 to 95.0 wt. %, 90.0 to 95.0 wt. %, 30.0 to 90.0 wt. %, 40.0
to 90.0 wt. %, 50.0 to 90.0 wt. %, 60.0 to 90 wt. %, 70.0 to 90.0
wt. %, 80.0 to 90.0 wt. %, 30.0 to 80.0 wt. %, 40.0 to 80.0 wt. %,
50.0 to 80.0 wt. %, 60.0 to 80 wt. %, 70.0 to 80.0 wt. %, 30.0 to
70.0 wt. %, 40.0 to 70.0 wt. %, 50.0 to 70.0 wt. %, 60.0 to 70 wt.
%, 30.0 to 60.0 wt. %, 40.0 to 60.0 wt. %, about 50.0 wt. %, 30.0
to 40.0 wt. %, 30.0 to 50.0 wt. %, or 40.0 to 50.0 wt. %.
[0037] In particular embodiments, the aromatics comprise
.gtoreq.10.0 wt. % paraxylene based on the weight of the aromatics.
The upper limit on the amount of para-xylene in the aromatics of
the hydrocarbon component of the product stream may be 10.0 wt. %,
20.0 wt. %, 30.0 wt. %, 40.0 wt. %, 45.0 wt. %, 50.0 wt. %, 55.0
wt. %, 60.0 wt. %, 65.0 wt. %, 70.0 wt. %, 80.0 wt. %, 90.0 wt. %,
95.0 wt. %, or 100.0 wt. %. The lower limit of the amount of
para-xylene in the aromatics portion of the hydrocarbon of the
product stream exiting reactor 103 may be 10.0 wt. %, 20.0 wt. %,
30.0 wt. %, 40.0 wt. %, 45.0 wt. %, 50.0 wt. %, 55.0 wt. %, 60.0
wt. %, 65.0 wt. %, 70.0 wt. %, 80.0 wt. %, 90.0 wt. %, or 95.0 wt.
%. Ranges of temperatures expressly disclosed include combinations
of any of the above-enumerated upper and lower limits, e.g., 10.0
to 95.0 wt. %, 20.0 to 80.0 wt. %, 30.0 to 70.0 wt. %, 40.0 to 60.0
wt. %, 10.0 to 50.0 wt. %, 20.0 to 60.0 wt. %, or 30.0 to 50.0 wt.
%, etc.
[0038] In particular embodiments, the hydrocarbons of the product
stream comprises .gtoreq.80.0 wt. % of aromatics, based on the
weight of the hydrocarbon, and .ltoreq.30.0 wt. % of the aromatics
comprise durene, based on the weight of the aromatics. In
particular embodiments, the amount of aromatics in the hydrocarbon
of the product stream may be 80.0 to 100.0 wt. %, 85.0 to 100.0 wt.
%, 90.0 to 100.0 wt. %, 95.0 to 100.0 wt. %, 80.0 to 95.0 wt. %,
85.0 to 95.0 wt. %, 90.0 to 95.0 wt. %, 80.0 to 90.0 wt. %, or 85.0
to 95.0 wt %; and the amount of durene in the aromatics comprises 0
to 30.0 wt. %, 0 to 25.0 wt. %, 0 to 20.0 wt. %, 0 to 15.0 wt. %, 0
to 10.0 wt. %, 0.0 to 5.0 wt. %, 0 to 2.5 wt. %, 0 to 1.0 wt. %,
1.0 to 30.0 wt. %, 1.0 to 25.0 wt. %, 1.0 to 20.0 wt. %, 1.0 to
15.0 wt. %, 1.0 to 10.0 wt. %, 1.0 to 5.0 wt. %, 1.0 to 2.5 wt. %,
2.5 to 30.0 wt. %, 2.5 to 25.0 wt. %, 2.5 to 20.0 wt. %, 2.5 to
15.0 wt. %, 2.5 to 10.0 wt. %, 2.5 to 5.0 wt. %, 5.0 to 30.0 wt. %,
5.0 to 25.0 wt. %, 5.0 to 20.0 wt. %, 5.0 to 15.0 wt. %, 5.0 to
10.0 wt. %, 10.0 to 30.0 wt. %, 10.0 to 25.0 wt. %, 10.0 to 20.0
wt. %, 10.0 to 15.0 wt. %, 15.0 to 30.0 wt. %, 15.0 to 25.0 wt. %,
15.0 to 20.0 wt. %, 20.0 to 30.0 wt. %, 20.0 to 25.0 wt. %, or 25.0
to 30.0 wt. %.
[0039] One of the products in the product stream exiting reactor
103 is hydrogen. Preferably hydrogen is present in an amount
.gtoreq.0.05 wt. %. The upper limit on the amount of hydrogen in
some embodiments is 5.0 wt. %, 4.0 wt. %, 3.0 wt. %, 2.0 wt. %, 1.0
wt. %, 0.50 wt. %, 0.40 wt. %, 0.30 wt. %, 0.20 wt. %, 0.10 wt. %,
or 0.05 wt. %. The lower limit on the amount of hydrogen in some
embodiments is 5.0 wt. %, 4.0 wt. %, 3.0 wt. %, 2.0 wt. %, 1.0 wt.
%, 0.50 wt. %, 0.40 wt. %, 0.30 wt. %, 0.20 wt. %, 0.10 wt. %, or
0.05 wt. %. Ranges of temperatures expressly disclosed include
combinations of any of the above-enumerated upper and lower limits,
e.g., 0.05 wt. % to about 5.0 wt. %, 0.10 to 4.0 wt. %, 0.2 to 3.0
wt. %, 0.4 to 2.0 wt. %, or 0.5 to 1.0 wt. %.
[0040] In particular embodiments, the product stream from reactor
103 comprises .ltoreq.1.0 wt. % carbon monoxide, the weight percent
of carbon monoxide being based on the total weight of the product
stream. Exemplary amounts of carbon monoxide include 0 to 1.0 wt.
%, 0 to 0.9 wt. %, 0 to 0.8 wt. %, 0 to 0.7 wt. %, 0 to 0.6 wt. %,
0 to 0.5 wt. %, 0 to 0.4 wt. %, 0 to 0.2 wt. %, 0 to 0.1 wt. %, 0.1
to 0.9 wt. %, 0.1 to 0.8 wt. %, 0.1 to 0.7 wt. %, 0.1 to 0.6 wt. %,
0.1 to 0.5 wt. %, 0.1 to 0.4 wt. %, 0.1 to 0.3 wt. %, 0.1 to 0.2
wt. %, 0.2 to 0.9 wt. %, 0.2 to 0.8 wt. %, 0.2 to 0.7 wt. %, 0.2 to
0.6 wt. %, 0.2 to 0.5 wt. %, 0.2 to 0.4 wt. %, 0.2 to 0.3 wt. %,
0.3 to 0.9 wt. %, 0.3 to 0.8 wt. %, 0.3 to 0.7 wt. %, 0.3 to 0.6
wt. %, 0.3 to 0.5 wt. %, 0.3 to 0.4 wt. %, 0.4 to 0.9 wt. %, 0.4 to
0.8 wt. %, 0.4 to 0.7 wt. %, or 0.4 to 0.6 wt. %. Low carbon
monoxide production is desirable in combination with higher
hydrogen combinations in some embodiments.
[0041] The particularly desirable combination of products in the
reactor effluent is provided by selection of reaction conditions
for use in combination with the molecular sieve and Group 2-14
element. Thus, in particular embodiments, the reactor 103 is
operated at a weight hourly space velocity (WHSV) in the range of
from 0.50 to 12.0 hr.sup.-1. The WHSV may be 0.5 to 11.0 hr.sup.-1,
0.5 to 10.0 hr.sup.-1, 0.5 to 9.0 hr.sup.-1, 0.5 to 7.0 hr.sup.-1,
0.5 to 6.0 hr.sup.-1, 0.5 to 5.0 hr.sup.-1, 0.5 to 4.0 hr.sup.-1,
0.5 to 3.0 hr.sup.-1, 0.5 to 2.0 hr.sup.-1, 0.5 to 1.0 hr.sup.-1,
1.0 to 11.0 hr.sup.-1, 1.0 to 10.0 hr.sup.-1, 1.0 to 9.0 hr.sup.-1,
1.0 to 7.0 hr.sup.-1, 1.0 to 6.0 hr.sup.-1, 1.0 to 5.0 hr.sup.-1,
1.0 to 4.0 hr.sup.-1, 1.0 to 3.0 hr.sup.-1, 1.0 to 2.0 hr.sup.-1,
2.0 to 11.0 hr.sup.-1, 2.0 to 10.0 hr.sup.-1, 2.0 to 9.0 hr.sup.-1,
2.0 to 7.0 hr.sup.-1, 2.0 to 6.0 hr.sup.-1, 2.0 to 5.0 hr.sup.-1,
2.0 to 4.0 hr.sup.-1, 2.0 to 3.0 hr.sup.-1, 3.0 to 11.0 hr.sup.-1,
3.0 to 10.0 hr.sup.-1, 3.0 to 9.0 hr.sup.-1, 3.0 to 7.0 hr.sup.-1,
3.0 to 6.0 hr.sup.-1, 3.0 to 5.0 hr.sup.-1, 3.0 to 4.0 hr.sup.-1,
4.0 to 11.0 hr.sup.-1, 4.0 to 10.0 hr.sup.-1, 4.0 to 9.0 hr.sup.-1,
4.0 to 7.0 hr.sup.-1, 4.0 to 6.0 hr.sup.-1, or about 0.50
hr.sup.-1.
[0042] Additionally or alternatively, the first mixture comprising
the oxygenate is exposed in reactor 103 to a temperature
.gtoreq.400.degree. C. and a pressure .gtoreq.2 bar absolute. In
particular embodiments, the temperature may be 400.0 to
700.0.degree. C. The upper limit on the range of temperatures may
be 400.0.degree. C., 425.0.degree. C., 450.0.degree. C.,
475.0.degree. C., 500.0.degree. C., 525.0.degree. C., 550.0.degree.
C., 600.degree. C., 650.degree. C., or 700.degree. C. The lower
limit on the range of the temperature of reactor 103 may be
400.0.degree. C., 425.0.degree. C., 450.0.degree. C., 475.0.degree.
C., 500.0.degree. C., 525.0.degree. C., 550.0.degree. C.,
600.degree. C. Ranges of temperatures expressly disclosed include
combinations of any of the above-enumerated upper and lower limits.
Such temperature ranges may be used in combination with a reactor
pressure of 2.0 to 500.0 bar absolute. In particular embodiments,
the upper limit on the range of pressures may be 10.0 bar absolute,
50 bar absolute, 75.0 bar absolute, 100.0 bar absolute, 125.0 bar
absolute, 150.0 bar absolute, 175.0 bar absolute, 200.0 bar
absolute, 250.0 bar absolute, 300.0 bar absolute, 350.0 bar
absolute, 400 bar absolute, or 450 bar absolute, and the lower
limit may be 2.0 bar absolute, 5.0 bar absolute, 10.0 bar absolute,
50 bar absolute, 75.0 bar absolute, 100.0 bar absolute, 125.0 bar
absolute, 150.0 bar absolute, 175.0 bar absolute, 200.0 bar
absolute, 250.0 bar absolute, or 300.0 bar absolute. Ranges and
combinations of temperatures and pressures expressly disclosed
include combinations of any of the above-enumerated upper and lower
limits.
[0043] The product stream from reactor 103 is provided via a line
104 to first separation unit 105 for separation into (i) at least
one water-rich stream 106, (ii) at least one aromatic-rich
hydrocarbon stream 107, and (iii) at least one aromatic-depleted
hydrocarbon stream 108. First separation unit 105 may be any
suitable separation means, e.g., distillation tower, simulated
moving-bed separation unit, high pressure separator, low pressure
separator, flash drum, etc. Optionally, at least a portion of
aromatics-rich hydrocarbon stream 107 may be recycled to reactor
103 via recycle line 107a, e.g., by combination directly or
indirectly with the first mixture in line 101. In particular
embodiments, wherein .gtoreq.50.0 wt. %, 50.0 to 100 wt. %, 60.0 to
95.0 wt. %, 70.0 to 90.0 wt. %, 80.0 to 85.0 wt. %, of the first
mixture's aromatics are the recycled aromatics, weight percents
being based on the total amount of aromatics in the first
mixture.
[0044] Optionally, at least a portion of aromatic-depleted
hydrocarbon stream 108 exiting first separation unit 105 may be
recycled to reactor 103, e.g., by combination, directly or
indirectly, with line 101. In another embodiment, oxygenates in
aromatics-depleted hydrocarbon stream 108 may be recovered
therefrom. At least a portion of the recovered oxygenates may
thereafter be provided to reactor 103. Additionally or
alternatively, at least one of ethylene, propylene, and butylenes
may be recovered from at least a portion of the aromatics-depleted
hydrocarbon stream 108.
[0045] With continuing reference to FIG. 1, FIG. 2 schematically
depicts a process 200 according to particular embodiments. The
aromatic-rich hydrocarbon stream 107 is provided to a second
separation unit 209 configured to separate the aromatic-rich stream
into (i) at least one first stream 210 comprising oxygenate and
C.sub.6 and/or C.sub.7 aromatics, (ii) at least one second stream
211 comprising oxygenate and C.sub.8 aromatics, and (iii) at least
one third stream 212 comprising oxygenate and C.sub.9+ aromatics.
Second separation unit 209 may be any device or process suitable
for performing such a separation, e.g. distillation tower,
simulated moving-bed separation unit, high pressure separator, low
pressure separator, flash drum, etc.
[0046] With continuing reference to FIGS. 1 and 2, FIG. 3
schematically depicts a process 300 according to particular
embodiments. Optionally, the first stream 210 may be provided to a
third separation unit 313 configured to separate from the first
stream 210 a first oxygenate stream 314 and a second aromatics-rich
stream 315, the aromatics-rich stream 315 comprising C.sub.6 and/or
C.sub.7 aromatics. Optionally, at least a portion of first
oxygenate stream 314 may be recycled to reactor 103, e.g., by
combining with the first mixture in line 101, e.g., via line 107a.
Third separation unit 313 may be any separation unit suitable for
such a separation, e.g., distillation tower, simulated moving-bed
separation unit, high pressure separator, low pressure separator,
flash drum, etc. In particular embodiments, the second
aromatics-rich stream 315 is provided to a recovery unit 316 for
recovering benzene and or toluene therefrom via line 317. At least
a portion of residual fraction 318 exiting recovery unit 316 may be
combined with the first mixture and provided to the reactor 103 via
line 101, e.g., via recovery line 107a. Optionally, at least a
portion of the second aromatics-rich stream 315, benzene, or
toluene 317 is provided to a toluene alkylation, toluene
disproportionation or transalkylation unit to produce xylenes (not
shown in FIG. 3). Toluene alkylation is described in more detail
in, for example, U.S. Pat. Nos. 6,423,879; 6,642,426; 6,388,156;
7,799,962; 8,048,388; 8,399,727; and 8,344,197. Toluene
disproportionation is described in more detail in, for example,
U.S. Pat. Nos. 5,993,642; 6,039,864; 6,198,013; and 6,486,373.
Transalkylation is described in more detail in, for example, U.S.
Pat. Nos. 7,553,791; 8,071,828; 8,183,424; and 8,481,443.
[0047] With continuing reference to FIGS. 1-3, FIG. 4 schematically
depicts a process 400 according to particular embodiments. Such
embodiments, which may optionally include the separation scheme of
process 300, include separating from the second stream 211 a second
oxygenate stream 419 and a third aromatics-rich stream 420 in a
fourth separation unit 421. Fourth separation unit 421 may be any
device or process suitable for performing such a separation, e.g.
distillation tower, simulated moving-bed separation unit, high
pressure separator, low pressure separator, flash drum, etc.
Optionally, at least a portion of second oxygenate stream 419 may
be recycled to reactor 103, e.g., by combining directly or
indirectly with the first mixture in line 101, e.g., via recycle
line 107a. Typically, the third aromatics-rich stream 420 comprises
C.sub.8+ aromatics. Third aromatics-rich stream 420 may be provided
to a second recovery unit 422 for recovering para-xylene therefrom.
At least a portion of residual fraction 423 exiting recovery unit
422 may be combined with the first mixture and provided to the
reactor 103 via line 101, e.g., via recycle line 107a. Optionally,
at least a portion of the para-xylene depleted residual fraction
423 may be sent to a xylenes isomerization unit to produce a mixed
xylenes stream from which para-xylene may be recovered.
[0048] With continuing reference to FIGS. 1-4, FIG. 5 schematically
depicts a process 500 according to particular embodiments. Process
500 may, additionally or alternatively, include separating third
stream 212 by any suitable means 524 into a third oxygenate stream
525 and a fourth aromatics-rich stream 526, the fourth
aromatics-rich stream comprising C.sub.9+ aromatics. Optionally, at
least a portion may be recycled to reactor 103, e.g., by combining
directly or indirectly with the first mixture in line 101, e.g.,
via recycle line 107a. Fourth aromatics stream 526 may optionally
be provided to a transalkylation unit 527 to transalkylate at least
a portion of the fourth aromatics-rich stream to produce xylenes.
Optionally, at least a portion of third oxygenate stream 525 and/or
at least a portion of residual fraction 528 exiting transalkylation
unit 527 may be recycled, directly or indirectly, to reactor 103,
e.g., by combining with the first mixture in line 101 via recycle
line 107a.
[0049] It has also been found that recycling and combining at least
a portion of the aromatics in the hydrocarbon product with the
oxygenate unexpectedly leads to one or more of the following
advantages. In particular embodiments, recycling and combining at
least a portion of the aromatics in the hydrocarbon product
provides an increase in the relative amount of aromatics in the
hydrocarbon product. The increase in aromatics may be achieved
without a significant increase in the rate of catalyst deactivation
and/or without a significant increase in the relative amount of
durene in the aromatic portion of the hydrocarbon product.
Advantageously and contrary to expectations, recycling and
combining with the oxygenate at least a portion of the aromatics in
the hydrocarbon product does not suppress methanol conversion to
aromatic products. Under particular conditions, recycling of the
aromatics can actually provide an overall increase in product
aromatics content. Surprisingly, the catalyst may not experience a
significant increase in deactivation rate, e.g., from over-reacting
the recycled aromatics, even at elevated reaction temperatures
(e.g., end of run conditions). And under certain conditions, the
relative amount of durene in the aromatic portion of the product
may not increase, even though recycling of xylenes to a chemical
environment rich in CH.sub.2 fragments would be expected to result
in alkylation to C.sub.9+ aromatics. At least a portion of the
olefins and paraffins in the hydrocarbon product may be recycled as
well, leading to further conversion of the olefins and paraffins to
aromatics without causing a significant increase in catalyst
deactivation.
[0050] The embodiments of the invention are illustrated in the
following examples.
Example 1
[0051] A first mixture comprising 100 wt % methanol is fed to a
fixed bed reactor operated at 450.degree. C. and 15 psig. The
reactor is packed with a catalyst comprising a ZSM-5 molecular
sieve loaded with 1 wt. % Zn and operated a WHSV of 2 hr-1. In this
example, essentially all of the feed is converted into
hydrocarbons. The effluent stream from the reactor is separated
into an aromatic and non-aromatic stream. The aromatics stream
contains benzene, toluene, C.sub.8 aromatics, and C.sub.9+
aromatics which are sent to a nearby aromatics plant for further
processing by transalkylation, toluene alkylation, toluene
disproportionation, or xylenes isomerization. The non-aromatic
stream contains light gases and oxygenates, C.sub.1 to C.sub.5
olefins and paraffins and a mixture of C.sub.5+ non-aromatics. This
non-aromatic overhead stream from the separator is then sent to an
olefins plant for further processing. Table 1 shows the resulting
product distribution.
TABLE-US-00001 TABLE 1 Reactor product distribution for feed
containing 100% methanol Product Wt. % C.sub.1-C.sub.4 paraffins
16.6 Ethylene 2.6 Propylenes 3.0 Butyenes 1.5 C.sub.5+ 3.1 Benzene
3.2 Toluene 15.5 C.sub.8 Aromatics 22.0 C.sub.9+ Aromatics 22.5
H.sub.2 0.7 Oxygenates 9.2 Methanol 100.0
Example 2
[0052] A first mixture comprising 100% methanol is fed to the
reactor under substantially the same conditions as in Example 1. In
this example, however, benzene and toluene in the product stream
are recycled back into the reactor. The product distribution, which
is shown in Table 2 shows a higher selectivity towards aromatics,
particularly the C.sub.8 and C.sub.9+ aromatics.
TABLE-US-00002 TABLE 2 Reactor product distribution for methanol
feed containing benzene and toluene Product (%) Wt. %
C.sub.1-C.sub.4 paraffins 9.2 Ethylene 1.2 Propylenes 1.0 Butylenes
0.5 C.sub.5+ 1.1 Benzene 3.1 Toluene 16.9 C.sub.8 Aromatics 33.1
C.sub.9+ Aromatics 29.5 H.sub.2 1.7 Oxygenates 2.6 Methanol
Conversion 100% Benzene Conversion 55.5% Toluene Conversion
54.5%
Example 3
[0053] In this example, a first mixture comprising methanol may be
provided to a fixed bed reactor which is operated at 400.degree. C.
and 1 atm. The reactor is packed with a catalyst comprising a ZSM-5
molecular sieve loaded with 1 wt. % Zn and having a Si:Al ratio of
100 to 10,000 and operated a WHSV of 6 hr.sup.-1. The product
stream comprises 17.2 wt. % C.sub.6-C.sub.9 aromatic compounds.
Example 4
[0054] Example 3 is substantially repeated, except that the reactor
temperature is 500.degree. C. The product stream comprises 19.4 wt.
%, C.sub.6-C.sub.9 aromatic compounds.
[0055] The description and examples above support one or more of
the following more specific Embodiments.
Embodiment 1
[0056] An aromatic production process, comprising (a) providing a
first mixture comprising .gtoreq.10.0 wt. % of at least one
oxygenate, based on the weight of the first mixture; (b) contacting
said first mixture with a catalyst to convert said first mixture to
a product stream comprising water, one or more hydrocarbons,
hydrogen, and one or more oxygenates, wherein A) said catalyst
comprises at least one molecular sieve and at least one element
selected from Groups 2-14 of the Periodic Table; B) said one or
more hydrocarbons comprise .gtoreq.30.0 wt. % of aromatics, based
on the weight of said one or more hydrocarbons in the product
stream; and C) separating from said product stream (i) at least one
water-rich stream, (ii) at least one aromatic-rich hydrocarbon
stream, and (iii) at least one aromatic-depleted hydrocarbon
stream.
Embodiment 2
[0057] A process according to Embodiment 1, wherein the first
mixture comprises .gtoreq.90.0 wt. % of methanol and/or DME, and
wherein the process further comprises separating from the
aromatic-rich hydrocarbon stream (i) at least one first stream
comprising oxygenate and C.sub.6 and/or C.sub.7 aromatics, (ii) at
least one second stream comprising oxygenate and C.sub.8 aromatics,
and (iii) at least one third stream comprising oxygenate and
C.sub.9+ aromatics.
Embodiment 3
[0058] A process according to any embodiment encompassed by
Embodiment 2, further comprising contacting at least a portion of
the first stream with the catalyst in step (b).
Embodiment 4
[0059] A process according to any embodiment encompassed by
Embodiment 2, further comprising separating from the first stream a
first oxygenate stream and a second aromatics-rich stream, the
aromatics-rich stream comprising C.sub.6 and/or C.sub.7
aromatics.
Embodiment 5
[0060] A process according to any embodiment encompassed by
Embodiment 4, further comprising recovering benzene and/or toluene
from the second aromatics-rich stream.
Embodiment 6
[0061] A process according to any embodiment encompassed by
Embodiments 4 or 5, further comprising sending at least a portion
of the second aromatics-rich stream or benzene and/or toluene to a
toluene alkylation, toluene disproportionation, or transalkylation
unit to produce xylenes.
Embodiment 7
[0062] A process according to any embodiment encompassed by
Embodiment 2, further comprising separating from the second stream
a second oxygenate stream and a third aromatics-rich stream, the
third aromatics rich stream comprising C.sub.8+ aromatics.
Embodiment 8
[0063] A process according to any embodiment encompassed by
[0064] Embodiment 7, further comprising recovering para-xylene and
a para-xylene depleted stream from the third aromatics-rich
stream.
Embodiment 9
[0065] A process according to any embodiment encompassed by
Embodiment 8, further comprising sending at least a portion of
para-xylene depleted stream to a xylenes isomerization unit to
produce a mixed xylenes stream and recovering para-xylene from the
mixed xylenes stream.
Embodiment 10
[0066] A process according to any embodiment encompassed by
Embodiment 2, further comprising separating from the third stream a
third oxygenate stream and a fourth aromatics-rich stream, the
fourth aromatics-rich stream comprising C.sub.9+ aromatics.
Embodiment 11
[0067] A process according to any embodiment encompassed by
Embodiment 10, further comprising transalkylating at least a
portion of the fourth aromatics-rich stream to produce xylenes.
Embodiment 12
[0068] A process according any embodiment encompassed by any of
Embodiments 4, 7, or 10, further comprising contacting at least a
portion of the first, the second, or the third oxygenate streams
with the catalyst in step (b).
Embodiment 13
[0069] A process according to any of Embodiments 1-12, further
comprising contacting at least a portion of the aromatic-depleted
hydrocarbon stream with the catalyst in step (b).
Embodiment 14
[0070] A process according to any of Embodiments 1-13, further
comprising recovering oxygenates from the aromatic-depleted
hydrocarbon stream.
Embodiment 15
[0071] A process according to any embodiment encompassed by
Embodiment 14, comprising contacting the catalyst in step (b) with
at least a portion of the recovered oxygenates.
Embodiment 16
[0072] A process according to any embodiment encompassed by
[0073] Embodiment 14 or 15, further comprising recovering at least
one of ethylene, propylene, and butylene from at least a portion of
the aromatic-depleted hydrocarbon stream.
Embodiment 17
[0074] An oxygenate conversion process, the process comprising: (a)
providing a first mixture, the first mixture comprising
.gtoreq.10.0 wt. % oxygenate based on the weight of the first
mixture; (b) exposing the first mixture at a temperature
.gtoreq.400.degree. C. at a pressure .gtoreq.2 bar absolute in the
presence of a catalyst to convert .gtoreq.90.0 wt. % of the first
mixture's oxygenate to (i) water, (ii) hydrocarbon, and (iii)
.ltoreq.1.0 wt. % carbon monoxide, the weight percents being based
on the weight of oxygenate in the first mixture, wherein (A) the
catalyst comprises .gtoreq.10.0 wt. % of at least one molecular
sieve and .gtoreq.0.1 wt. % of at least one element selected from
Groups 2-14 of the Periodic Table, the weight percents being based
on the weight of the catalyst, (B) the hydrocarbon comprises
.gtoreq.50.0 wt. % of aromatics, based on the weight of the
hydrocarbon; and (C) separating the aromatics from one or more of
(i) at least a portion of the water produced in step (b), (ii) any
unreacted oxygenate, or (iii) at least a portion of the
hydrocarbon.
Embodiment 18
[0075] A process according to any embodiment, wherein (i) the first
mixture comprises .gtoreq.25.0 wt. % oxygenate, based on the weight
of the first mixture, and (ii) the oxygenate comprises .gtoreq.90.0
wt. % based on the weight of the oxygenate of one or more of
alcohol, ether, carboxylic acid, carbon monoxide, or carbon
dioxide.
Embodiment 19
[0076] A process according to any embodiment, wherein the oxygenate
comprises .gtoreq.99.0 wt. % of methanol and/or dimethylether.
Embodiment 20
[0077] A process according to any embodiment encompassed by
Embodiments 17-19, wherein the oxygenate comprises .gtoreq.99.0 wt.
% of methanol, the exposing of step (b) is conducted at a WHSV in
the range of from 0.5 to 12 hr.sup.-1, the hydrocarbon comprises
.gtoreq.80.0 wt. % of aromatics, based on the weight of the
hydrocarbon, and .ltoreq.30.0 wt. % of the aromatics comprise
durene, based on the weight of the aromatics.
Embodiment 21
[0078] A process according to any embodiment, wherein the first
mixture further comprises .gtoreq.10.0 wt. % aromatics, based on
the weight of the first mixture.
Embodiment 22
[0079] A process according to any embodiment encompassed by
Embodiments 17-21, further comprising recycling at least a portion
of the separated aromatics from step (c) to step (a), wherein
.gtoreq.50.0 wt. % of the first mixture's aromatics are the
recycled aromatics.
Embodiment 23
[0080] The process of any embodiment, wherein the molecular sieve
comprises ZSM-5, and the Group 2-14 element comprises Zn.
[0081] While the present invention has been described and
illustrated by reference to particular embodiments, those of
ordinary skill in the art will appreciate that the invention lends
itself to variations not necessarily illustrated herein. For this
reason, then, reference should be made solely to the appended
claims for purposes of determining the enforceable scope of the
present invention.
[0082] All documents described herein are incorporated by reference
for purposes of all jurisdictions where such practice is allowed,
including any priority documents and/or testing procedures to the
extent they are not inconsistent with this text, provided however,
that any priority document not named in the initially filed
application or filing documents is NOT incorporated by reference
herein. As is apparent from the foregoing general description and
the specific embodiments, while forms of the invention have been
illustrated and described, various modifications can be made
without departing from the spirit and scope of the invention.
Accordingly, it is not intended that the invention be limited
thereby. Likewise, the term "comprising" is considered synonymous
with the term "including." Likewise whenever a composition, an
element or a group of elements is preceded with the transitional
phrase "comprising," it is understood that we also contemplate the
same composition or group of elements with transitional phrases
"consisting essentially of," "consisting of," "selected from the
group of consisting of," or "is" preceding the recitation of the
composition, element, or elements and vice versa.
* * * * *